/usr/share/doc/python-jmespath/README.rst is in python-jmespath 0.9.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | JMESPath
========
.. image:: https://badges.gitter.im/Join Chat.svg
:target: https://gitter.im/jmespath/chat
.. image:: https://secure.travis-ci.org/jmespath/jmespath.py.png?branch=develop
:target: http://travis-ci.org/jmespath/jmespath.py
JMESPath (pronounced "james path") allows you to declaratively specify how to
extract elements from a JSON document.
For example, given this document::
{"foo": {"bar": "baz"}}
The jmespath expression ``foo.bar`` will return "baz".
JMESPath also supports:
Referencing elements in a list. Given the data::
{"foo": {"bar": ["one", "two"]}}
The expression: ``foo.bar[0]`` will return "one".
You can also reference all the items in a list using the ``*``
syntax::
{"foo": {"bar": [{"name": "one"}, {"name": "two"}]}}
The expression: ``foo.bar[*].name`` will return ["one", "two"].
Negative indexing is also supported (-1 refers to the last element
in the list). Given the data above, the expression
``foo.bar[-1].name`` will return "two".
The ``*`` can also be used for hash types::
{"foo": {"bar": {"name": "one"}, "baz": {"name": "two"}}}
The expression: ``foo.*.name`` will return ["one", "two"].
API
===
The ``jmespath.py`` library has two functions
that operate on python data structures. You can use ``search``
and give it the jmespath expression and the data::
>>> import jmespath
>>> path = jmespath.search('foo.bar', {'foo': {'bar': 'baz'}})
'baz'
Similar to the ``re`` module, you can use the ``compile`` function
to compile the JMESPath expression and use this parsed expression
to perform repeated searches::
>>> import jmespath
>>> expression = jmespath.compile('foo.bar')
>>> expression.search({'foo': {'bar': 'baz'}})
'baz'
>>> expression.search({'foo': {'bar': 'other'}})
'other'
This is useful if you're going to use the same jmespath expression to
search multiple documents. This avoids having to reparse the
JMESPath expression each time you search a new document.
Options
-------
You can provide an instance of ``jmespath.Options`` to control how
a JMESPath expression is evaluated. The most common scenario for
using an ``Options`` instance is if you want to have ordered output
of your dict keys. To do this you can use either of these options::
>>> import jmespath
>>> jmespath.search('{a: a, b: b},
... mydata,
... jmespath.Options(dict_cls=collections.OrderedDict))
>>> import jmespath
>>> parsed = jmespath.compile('{a: a, b: b}')
>>> parsed.search('{a: a, b: b},
... mydata,
... jmespath.Options(dict_cls=collections.OrderedDict))
Specification
=============
If you'd like to learn more about the JMESPath language, you can check out
the `JMESPath tutorial <http://jmespath.org/tutorial.html>`__. Also check
out the `JMESPath examples page <http://jmespath.org/examples.html>`__ for
examples of more complex jmespath queries.
The grammar is specified using ABNF, as described in
`RFC4234 <http://www.ietf.org/rfc/rfc4234.txt>`_.
You can find the most up to date
`grammar for JMESPath here <http://jmespath.org/specification.html#grammar>`__.
You can read the full
`JMESPath specification here <http://jmespath.org/specification.html>`__.
Testing
=======
In addition to the unit tests for the jmespath modules,
there is a ``tests/compliance`` directory that contains
.json files with test cases. This allows other implementations
to verify they are producing the correct output. Each json
file is grouped by feature.
Discuss
=======
Join us on our `Gitter channel <https://gitter.im/jmespath/chat>`__
if you want to chat or if you have any questions.
|